Researchers Develop Process That Could Result in Higher Yield from Oil Shale
22 September 2008
|Results from the retort experiments for oil shale (OS) samples. Click to enlarge. Credit: ACS|
Researchers in Canada and Turkey have developed a new process that could lead to the more economical production of oil shale with increased yield. In laboratory-scale experiments, the researchers added inexpensive iron powder to four different types of oil shale combined with heating with electric coils. Production increased by more than 100% for one of the shale samples. Their study is scheduled for the November 19 issue of the journal Energy & Fuels.
Oil shale is a generic term applied to fine-grained sedimentary rock that contains significant amounts of kerogen, an organic precursor to oil and gas. Heated to the right temperature in the Earth’s crust, some types of kerogen release oil or gas. If such kerogens are present in high concentration in rocks, such as shale, and have not been heated to a sufficient temperature to release their hydrocarbons, they may form oil shale deposits.
The basics of releasing oil from oil shale is to heat the rock, either after mining in a retort, or in-situ via the use of electric heaters. (Earlier post.)
The easiest way to increase the efficiency of this method is to increase the thermal conductivity of the system or increase the reduction of the oil viscosity by using some additives. Metallic additives cause changes in the nature and the amount of fuel formed during in situ combustion.—Hascakir et al. (2008)
|Results from the in-situ heating simulations for oil shale (OS) samples. Click to enlarge. Data: Hascakir et al. (2008)|
The researchers used oil shale samples obtained from different oil shale deposits in Turkey and added three different iron powders at three different doses were used. The experimental results were simulated using a commercial reservoir simulator, where the data required for field-scale simulation were obtained through history matching of production data and temperature distribution inside the core. They also simulated field-scale application of in-situ electrical heating .
Because iron powders help increase the thermal conductivity of the system, heat transfer was accomplished more efficiently, yielding increased oil production at laboratory conditions. Also, iron additives have a catalytic effect that increases the reaction speed. The chemical reactions between iron powders and shale oil help to break the chemical bonds by increasing the temperature and magnetic effect of iron powders on the reduction of oil viscosity, which caused an increase in the oil production after the addition of iron powders.—Hascakir et al. (2008)
Introducing iron powder into the field for practical application with in-situ heating would be a critical enabler for this process. The researchers suggest that iron powders could be injected into the reservoir after mixing them with petroleum-based fluids, such as light oils or solvents. For fields shallow enough to support surface mining, a better solution would be adding the iron powders during the extraction process, they said.
The technical and economic feasibility analyses showed that electrical heating is still a marginal application, but the results proved that it is in an applicable range.—Hascakir et al. (2008)
A recent UC Berkeley analysis concluded that Shell’s in situ conversion process for oil shale produces an energy output of 1.2-1.6 times greater than the total primary energy inputs to the process. However, in the absence of capturing CO2 generated from electricity produced to fuel the process, well-to-pump GHG emissions are in the range of 30.6-37.1 grams of carbon equivalent per megajoule of refined fuel delivered (gCequiv/MJ RFD). These full-fuel-cycle emissions are 21%-47% larger than those from conventionally produced petroleum-based fuels. (Earlier post.)
Berna Hascakir, Tayfun Babadagli, and Serhat Akin (2008) Experimental and Numerical Simulation of Oil Recovery from Oil Shales by Electrical Heating. ASAP Energy Fuels, doi: 10.1021/ef800389v
And we thought oil from sands was difficult to do, now oil from rocks? What will we burn to heat the oil out?
I'm not buying 1.2 to 1.6 !
Surface mining? Not in my back yard.
How much is the clean up? Who will do it?
I think we really need to direct our resources elsewhere and maybe just use less for a while. We can 'start' with the right pressure in our tires... (I'm not kidding) it's part of the solution that costs nothing.
Posted by: Mark M | 22 September 2008 at 01:28 PM
Shaft mining is the way to go! They do it in Estonia all the time. There is an ecological disaster in the area.
But seriously, while shale mining and processing is an ugly mess, they are still a source of liquid hydrocarbons for the chemical industry.
Posted by: black ice | 22 September 2008 at 11:03 PM
en EROI of 1.6 is simply a disaster from an economic standpoin, plus it makes it impossible to scale, not mentionning the unacceptable environmental cost as well as water consumption. I bet these oil shale will stay in the ground for ever, better in vest in solar, wind, geothermal or even nuclear
Posted by: Trehugger | 23 September 2008 at 03:06 AM
The 1.6 EROI is a single analysis of a single method of recovery. Not gospel, and not set in stone. Multiple methods of extracting oil equivalent from shale have to be compared side by side by multiple investigators.
Instead, you have Luddites like Senator Ken Salazar of Colorado who want to shut down all study of oil shale. That type of loser mentality is pervasive among Salazar's comrades in the US Senate and US government in general. Time to shift to a can-do attitude. At least Canadians and Turks are trying to do something beyond pie in the sky wishful thinking.
Posted by: Alice Finkelstein | 23 September 2008 at 07:15 AM
On one occasion, Thomas A. Edison said:
"I would invest my money in solar energy"
Posted by: Jorge | 23 September 2008 at 08:57 AM
The problem of EROI is wall for extraction of oil-shale, and when you are at 1.2-1.6 the uncertainty of measurement can make you negative very fast. You really need disruptive ideas to improve that figure or a long time of incremental improvements, better not to count on it, Shell has been working 35 years on this and the result is not really promising. Given the envirinmental cost of extracting these oil shales I doubt it is worth it.
Posted by: Treehugger | 23 September 2008 at 10:42 AM
Edison was right, just ahead of his time.
Besides, pretty much every energy sourse on our planet is ultimately sourced from solar energy. so he was not wrong, technically speaking.
Posted by: | 23 September 2008 at 12:01 PM
We will eventually mine shale. The World's petro-chemical businesses will need the feedstocks, and for them several hundred dollars per barrel is not an obstacle.
There are still political, no longer scientific reasons, to worry about the the CO2 emissions. Unfortunately, the entire popular media and the conversation of tax raising politicians, remains that it is a problem.
Fotunately, the scientific community is starting to complain about the psuedo-scientific nonsense, and ad-hominem attacks, emanating from the true-believers. The absence of any warming, or any ill effects as postulated, is making the fools apparent that they are fools to all.
Posted by: stas peterson | 24 September 2008 at 11:42 AM
Again mister Stan Peterson scam take his fantasy for reality : in his idiotic reasoning he thinks that dollards can be converted in unit of energy. What he missed in his simplified thinking (as always) is that when the EROI is too low you can never catch up the cost of extraction even if the oil is expensive. Low EROI makes the economical breakheaven a moving target.
Sorry msr Sats Peterson but you are wring again this time
And we are still waiting for your reference about the "scientific community consensus that AWG is scientific non sense" I think we will be waiting for long...
Posted by: Treehugger | 24 September 2008 at 09:44 PM